1. Field of the Invention
The invention relates to an electronic device. Particularly, the invention relates to an electronic device capable of switching load units according to an input voltage.
2. Description of Related Art
Since a light emitting diode (LED) has advantages of long service life, small size, high shock resistance, low heat generation and low power consumption, it is widely used as indicators or light sources in various home appliances and equipments. In recent years, the LEDs are developed to have features of multi-color (multicolor) and high brightness, so that application fields thereof have been extended to large outdoor billboards, traffic lights and related fields. In the future, the LEDs could even become main illumination light sources having features of power saving and environmental protection.
Generally, a control circuit of the LED first converts an alternating-current (AC) voltage into a direct-current (DC) voltage or a DC current, and then uses the stable DC voltage or the DC current to control a brightness of the LED. In other words, the conventional control circuit of the LED is generally embedded with an AC-DC converter or equipped with a transformer so as to control the LED through an AC commercial power, though in this case, not only a hardware size of the control circuit of the LED is increased, but also application convenience of the LED is limited.